Method of equalizing the color effect of cotton yarn to that of cuprammonium silk



Patented Mar. 24, 1931 UNITED STATES PATENT OFFICE FRITZ STEINBERG, OFBARMEN-LANGERFELD, GERMANY, ASSIGNOB T0 AMERICAN BEMBERG CORPORATION, OFNEW YORK, N. Y., A CORPORATION OF DELAWARE METHOD OF EQUALIZING THECOLOR EFFECT OF COTTON'YABN TO THAT OF CUPBAMMONIUM SILK No Drawing.Application filed November 26, 1930, Serial No. 498,439, and in GermanyNovember 25, 1929.

In dyeing material which. is composed partly of two difierent materials,for example, cotton and cuprammonium (Bemberg) yarn used in hosiery,etc., it has been noticed are not as resistant, and may not be wet thecotton, made up into a strand, is treated with a copper ammoniasolution. This produces a slight swelling and loosening of the filamentsWhile the copper ammonium caus tie is being absorbed. The cotton yarn islater treated in order to remove the copper contained in the filaments.The yarn is then passed through several washings until a new tralreaction occurs, or is reached, and the yarn is dried. It isadvantageous to apply tension to the yarn during these treatments inorder to avoid shrinkage.

For practical reasons this treatment may be divided into a pro-treatmentwith a diluted solution and a post-treatment wherein a somewhat strongersolution is used, and whereby the solution first usedg forpost-treatment may be later used for the pro-treatment since the coppercontent decreases with the use of the solution.

The object of the pro-treatment is mainly to wet the cotton in order toinsure a uniform absorption of the solution in the subsequentpost-treatment. The application of tension is, ordinarily, not necessaryin the pro-treatment, although some tension will lessen the danger of aminor shrinkage.

This treatment imparts to the cotton yarns the same dyeing aflinity asis found in the cuprammonium silk, and will offset the disadvantagesfound hitherto, and enumerated supra.

The method may be more clearly seen from a study of the followingexample:

The cotton is subjected, first, to a pretreatment with a wettingalkaline solution made from a previously used post-treatment solution.To obtain this solution, the used solution containing 0.53-0.58 percentof.copper is diluted by water until a copper content of 0.39-0.40results. The ratio of the textile material to the bath is 1: 20 for thispro-treatment wetting caustic solution.

As the etching caustic or post-treatment solution a copper ammoniumsolution containing from 0704.75 percent cop er and 17-20 percentammonia is employe This may be prepared b dissolving the correspondingquantity 0 copper in concentrated ammonia,.so that a copper content offrom 1.1-1.3 percent copper is obtained. This solution is then dilutedwith a used solution until a copper content of 0.70-0.75 results. Theproportion of textile material to the solution is 1 :14.5.'

Subsequently to this treatment, a further treatment with an ammoniacalammonium sulphate is used in order to remove the coppep. In order to'prepare this solution 2.5 liters of ammonia of a specific weight of0.901 and 0.5 liters of sulphuric acid of a for the concentratedsolution and the ammonium sulphate treatment, but also for the wetting,mercerizing machines may be advantageously employed. By this means theyarn is either completely immersed or the liquid for the treatment isapplied between the rolls of the mercerizing machine by means of pipes.The liquids, used in treating the yarn may be applied several times byuse of a circular pumping system, and thereby a more uniform effect maybe obtained.

Having now fully disclosed my invention as required by the patentstatutes, what I claim is:

1. In a method for equalizing the dyeing effect of a fabric comprising amixture of cotton and cuprammonium yarn, the step of treating the cottonwith a copper-oxide-ammonia solution- 2. In a method as outlined inclaim 1, in which a subsequent treatment with ammonium sulphate isemployed prior to the dyeing step.

3. In a method for equalizing the dyeing eliect of a textile comprisinga mixture of cotton and cuprammonium yarn, the steps of treating thecotton yarn with a copper oxide ammonia solution, an ammonium sulphatesolution and then washing and drying, in

successive steps.

4, A method for equalizing the dyeing effect of a textile materialcomprising a mixture of cotton and cuprammonium. silk,

wherein the cotton is first treated with a bath containing 0.39 to 0.4:0percent copper, then with a bath containing 0.70 to 0.75 percent copper,then with an ammonium sulphate. bath, and subsequently washed and dried.

25 In testimony whereof I affix my signature.

FRITZ STEINBERG.

